Considering pressure physics and the ability of the hoses to swell this actually makes perfect sense, thanks for taking the time to explain. Come to think of it I have been chasing a small boost leak on the intercooler outlet and expanded hoses could be the culprit.

It ends up be being cheaper just replacing the hoses than chasing down the issue. I never threw a code so people shouldn't expect one. The problem has been ongoing for some time as it was only leaking at higher boost levels. The silicone hose will leak at some point (for everyone) and you will be able see fresh oil vapor at the leak point. You will notice turbo lag, flat power delivery, minor boost oscillations and 5-15% reduction in gas mileage that seems to happen all of sudden then gets worse.